The statements in this section merely provide background information related to the present disclosure and may not constitute prior art.
Angle measuring devices are known in the prior art. These devices are used to acquire angular positions and rotational speeds of, for example, crankshafts and camshafts of internal combustion engines. An angle measuring device that is a rotating device can be constructed as a multi-pole encoder with a magnetized elastomer, or as a gear wheel. In the case of a rotating device constructed as a gear wheel, the teeth and gaps of the gear wheel function as signal-generating elements, in each case a tooth and a gap being combined to form a unit. Such a gear normally comprises 58 teeth and gaps which are positioned on the circumference of the gear wheel following one another at intervals of 6°. At one point, by leaving out 2 teeth and by combining three adjacent gaps, a reference point is formed, which frequently corresponds to the top dead center of a cylinder of an internal combustion engine.
The well-established geometry of a rotating device generates a signal of 57 regular periods of 6° and one irregular period of 18°. This irregular singularity allows generating an electric period of 18° that is used as position reference for engine management. The regular portions of the impulse wheel generates one impulse every 6° that is used by engine management to determine speed and shaft position. The disadvantage of such system is that speed information is lost in the irregular position of the rotating device.